Medical Dictionary: Glossary (P)

Pacemaker A system that sends electrical impulses to the heart in order to set the heart rhythm.

Pachyderma Thick skin, similar to a pachyderm (an elephant, rhinoceros, or hippopotamus). Pachyderma can occur in several medical conditions, such as chronic lymphedema.

Pachyonychia Elephant nail, a fingernail or toenail that is abnormally thick.

Palate The roof of the mouth in which the front portion is bony (hard palate), and the back portion is muscular (soft palate).

Palliation To palliate a disease is to treat it partially, but not cure it completely.

Pancreas A spongy, tube-shaped organ that is about 6 inches long and is located in the back of the abdomen, behind the stomach. Secretes digestive enzymes and some cells inside it also secrete insulin.

Paralysis Loss of voluntary movement (motor function). Paralysis that affects only one muscle or limb is partial paralysis, also known as palsy; paralysis of all muscles is total paralysis.

Parotids The pair of Salivary glands situated in front of the ears.

Paroxysm This is a violent attack of symptoms. It may be due to the sudden occurrence of symptoms or the acute exacerbation (the abrupt worsening) of preexisting symptoms.

Pasteurization A method of treating food by heating it to a certain point to kill pathogenic (disease-causing) organisms but not harm the flavor or quality of the food.